In some respects, it’s entirely different from the “Upstairs, Downstairs” machinations in “Spartacus.” But in other ways, “Black Sails” really does play many of the same beats.

The violence in “Spartacus” was stylized and cartoony; it’s more realistic in “Black Sails.” “Spartacus” offered liberal graphic sex scenes, and “Black Sails” does the same, particularly when it comes to two lesbian characters.

Through its first two hours, “Black Sails” is entertaining enough but not nearly as addictive as “Spartacus” came to be through its first season; perhaps in time that will change.

The story begins as pirates from the Walrus invade another ship where a cowardly buccaneer and a cook hide below deck. The coward, John Silver (Luke Arnold), exits the hold alive and claims to be a cook, keeping himself useful to pirate Flint (Toby Stephens), captain of the Walrus.

Flint’s leadership is in doubt as a challenger has come forward to usurp the pirate captain who has hatched a secretive plan to make them all wealthy, but he hasn’t shared details of the plan with his crew. Loyal quartermaster Gates (Mark Ryan) does his best to sway votes in favor of Flint, who turns out to excel at saving himself with an able assist from boatswain Billy Bones (Tom Hopper).

When not on the high seas, the Walrus is offloading its stolen goods in Nassau, the Bahamas, where foul-mouthed Eleanor Guthrie (Hannah New) holds sway. Her father, the wealthiest blackmailer in the Bahamas, installed her as his adjutant in Nassau. She in turn relies on one of his former slaves, Mr. Scott (Hakeem Kae-Kazim), as her assistant. Eleanor’s also involved with Max (Jessica Parker Kennedy), a prostitute in the local brothel, which is where the show’s love scenes come in.

Eleanor makes a pact with Capt. Flint, which puts her at odds with her former love, pirate captain Charles Vane (Zach McGowan), who looks a bit like Fabio or a stray member of a 1980s hair-metal band, similar to Gannicus in “Spartacus.” (Maybe that’s a prerequisite for landing a show on Starz?)

All of these characters intermingle, plot against one another, come together and break apart while in Nassau. In addition to the character soap operas at play, “Black Sails” also explores the notion that this pirate frontier era is nearing its end.

“Civilization is coming and it means to exterminate us,” Flint warns.

That’s an interesting backdrop for all the sex and violence that “Black Sails” puts front and center. As created by writers Jonathan E. Steinberg (“Human Target,” “Jericho”) and Robert Levine (“Human Target,” “Harper’s Island”), “Black Sails” has its humorous moments — episode two has more of them than the pilot — most notably through the scoundrel John Silver. “Black Sails” doesn’t take itself too seriously and it’s also fairly complex with its three main groups of characters.

At a news conference earlier this month, Steinberg said he wanted to make a pirate show in part because no one else has. That will change later this year when NBC debuts “Crossbones” with John Malkovich, but for now “Black Sails” has the market cornered on TV.

“No one has dug into this world, deep into the bedrock of it, into the reality of what it was like to wake up in the morning and know that this was your life; that if you were going to survive, if you were going to eat, you needed to take from somebody in this environment,” Steinberg said. “It’s a very different tone than any other pirate story I’d ever heard.”

Steinberg said female characters are intentionally presented in a more fleshed-out form than, say, the wenches chased in circles on the Pirates of the Caribbean ride at Disneyland.

“It was really important to us that if we were going to explore this world, gender had to be a part of that, well beyond just stock wenches and the occasional cross-dressing pirate,” he said. “They had very specific challenges, and they had very specific expectations. We’ve always seen the show as a bit of a Western. It’s a frontier story. It’s a story about necessity, day-to-day survival, breaking down social convention.”

As for the nudity and sex — staples of Starz shows but more weighted toward the female characters in “Black Sails” than in “Spartacus,” which offered equal-opportunity nudity — Steinberg said it was necessary for the show to feel real.

“It needed to feel like a world where the absence of government, the absence of any kind of authority had meaning,” he said. “…People have sex, and they almost certainly have sex in a world in which none of them really have any jobs and they are living in the Caribbean. We’ve gotten into stories, especially in the second season, where whole stories are wrapped up in the very minute details of sexual relationships, because they are. And I think that’s what life is.”

For actor Toby Stephens, the son of “Downton Abbey” star Maggie Smith (aka the Dowager Countess), “Black Sails” is a preferable work environment to a genteel costume drama.

“Any day of the week I would prefer to be doing the show that I’m doing right now,” he said. “I appreciate ‘Downton Abbey’ for what it is. I have to say I don’t regularly tune in. It’s not really the kind of show that I enjoy. I appreciate what my mum does in it. She’s great in it. ... Playing this kind of thing, for me, is like going on an exotic vacation because we just don’t do this kind of stuff in the U.K. We do a lot of the kind of stuff like ‘Downton Abbey,’ a lot of period drama, a lot of detective stuff. For me, that’s kind of like, yeah, I’ve seen that. I’ve done it. I don’t want to do it for the rest of my life.”